6.7-stable review patch. If anyone has any objections, please let me know.
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From: Sabrina Dubroca sd@queasysnail.net
[ Upstream commit 13114dc5543069f7b97991e3b79937b6da05f5b0 ]
When the decrypt request goes to the backlog and crypto_aead_decrypt returns -EBUSY, tls_do_decryption will wait until all async decryptions have completed. If one of them fails, tls_do_decryption will return -EBADMSG and tls_decrypt_sg jumps to the error path, releasing all the pages. But the pages have been passed to the async callback, and have already been released by tls_decrypt_done.
The only true async case is when crypto_aead_decrypt returns -EINPROGRESS. With -EBUSY, we already waited so we can tell tls_sw_recvmsg that the data is available for immediate copy, but we need to notify tls_decrypt_sg (via the new ->async_done flag) that the memory has already been released.
Fixes: 859054147318 ("net: tls: handle backlogging of crypto requests") Signed-off-by: Sabrina Dubroca sd@queasysnail.net Link: https://lore.kernel.org/r/4755dd8d9bebdefaa19ce1439b833d6199d4364c.170913264... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/tls/tls_sw.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-)
diff --git a/net/tls/tls_sw.c b/net/tls/tls_sw.c index 1fd37fe13ffd8..211f57164cb61 100644 --- a/net/tls/tls_sw.c +++ b/net/tls/tls_sw.c @@ -52,6 +52,7 @@ struct tls_decrypt_arg { struct_group(inargs, bool zc; bool async; + bool async_done; u8 tail; );
@@ -286,15 +287,18 @@ static int tls_do_decryption(struct sock *sk, }
ret = crypto_aead_decrypt(aead_req); + if (ret == -EINPROGRESS) + return 0; + if (ret == -EBUSY) { ret = tls_decrypt_async_wait(ctx); - ret = ret ?: -EINPROGRESS; - } - if (ret == -EINPROGRESS) { - return 0; - } else if (darg->async) { - atomic_dec(&ctx->decrypt_pending); + darg->async_done = true; + /* all completions have run, we're not doing async anymore */ + darg->async = false; + return ret; } + + atomic_dec(&ctx->decrypt_pending); darg->async = false;
return ret; @@ -1593,8 +1597,11 @@ static int tls_decrypt_sg(struct sock *sk, struct iov_iter *out_iov, /* Prepare and submit AEAD request */ err = tls_do_decryption(sk, sgin, sgout, dctx->iv, data_len + prot->tail_size, aead_req, darg); - if (err) + if (err) { + if (darg->async_done) + goto exit_free_skb; goto exit_free_pages; + }
darg->skb = clear_skb ?: tls_strp_msg(ctx); clear_skb = NULL; @@ -1606,6 +1613,9 @@ static int tls_decrypt_sg(struct sock *sk, struct iov_iter *out_iov, return err; }
+ if (unlikely(darg->async_done)) + return 0; + if (prot->tail_size) darg->tail = dctx->tail;